Eh, this is what I see it be.
Chespin: normal-high HP, high Defense, high Attack, low Sp. Attack, low Sp. Defense, low Speed
(The fighter/knight class generally has high Attak, Defense, and durability, but low speed and resistance to magical attributes)
Fennekin: low HP, very low Defense, very low Attack, very high Sp. Attack, very high Sp. Defense, normal-high Speed
(The mage class generally has very high magical abilities and ok speed, while suffering greatly in durability, strength, and defense)
Froakie: low HP, low Defense, very high Attack, low Sp. Attack, low Sp. Defense, very high Speed.
(The rogue/assassin/thief class generall is very frail, and having little magical properties, but very agile and physical strength)
Eh, what I see them become based on classes.